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Bryant DURAPAC PLUS 581B User Manual

Page 18

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18

Table 3 — Supply Air Sensor

Temperature/Resistance Values

G. EconoMi$er IV Control Modes

Determine the EconoMi$er IV control mode before set up of the
control. Some modes of operation may require different sensors.
Refer to Table 4. The EconoMi$er IV is supplied from the fac-
tory with a supply air temperature sensor and an outdoor air
temperature sensor. This allows for operation of the
EconoMi$er IV with outdoor air dry bulb changeover control.
Additional accessories can be added to allow for different
types of changeover control and operation of the EconoMi$er
IV and unit.

Outdoor Dry Bulb Changeover

The standard controller is shipped from the factory config-
ured for outdoor dry bulb changeover control. The outdoor
air and supply air temperature sensors are included as stan-
dard. For this control mode, the outdoor temperature is com-
pared to an adjustable set point selected on the control. If the
outdoor-air temperature is above the set point, the
EconoMi$er IV will adjust the outside air dampers to mini-
mum position. If the outdoor-air temperature is below the set
point, the position of the outdoor-air dampers will be con-
trolled to provide free cooling using outdoor air. When in this
mode, the LED next to the free cooling set point potentiome-
ter will be on. The changeover temperature set point is con-
trolled by the free cooling set point potentiometer located on
the control. See Fig. 32. The scale on the potentiometer is A,
B, C, and D. See Fig. 33 for the corresponding temperature
changeover values.

Differential Dry Bulb Control

For differential dry bulb control the standard outdoor dry
bulb sensor is used in conjunction with an additional acces-
sory dry bulb sensor (part number CRTEMPSN002A00). The
accessory sensor must be mounted in the return airstream.
See Fig. 34. Wiring is provided in the EconoMi$er IV wiring
harness. See Fig. 27.

In this mode of operation, the outdoor-air temperature is
compared to the return-air temperature and the lower tem-
perature airstream is used for cooling. When using this mode
of changeover control, turn the enthalpy set point potentiom-
eter fully clockwise to the D setting. See Fig. 32.

Table 4 — EconoMi$er IV Sensor Usage

*CRENTDIF004A00 and CRTEMPSN002A00 accessories are used on many

different base units. As such, these kits may contain parts that will not be
needed for installation.

†33ZCSENCO2 is an accessory CO

2

sensor.

**33ZCASPCO2 is an accessory aspirator box required for duct-mounted appli-

cations.

††CRCBDIOX005A00 is an accessory that contains both 33ZCSENCO2 and

33ZCASPCO2 accessories.

TEMPERATURE (F)

RESISTANCE (ohms)

–58

200,250

–40

100,680

–22

53,010

–4

29,091

14

16,590

32

9,795

50

5,970

68

3,747

77

3,000

86

2,416

104

1,597

122

1,080

140

746

158

525

176

376

185

321

194

274

212

203

230

153

248

116

257

102

266

89

284

70

302

55

APPLICATION

ECONOMI$ER IV WITH OUTDOOR AIR

DRY BULB SENSOR

Accessories Required

Outdoor Air

Dry Bulb

None. The outdoor air dry bulb sensor

is factory installed.

Differential

Dry Bulb

CRTEMPSN002A00*

Single Enthalpy

HH57AC078

Differential

Enthalpy

HH57AC078

and

CRENTDIF004A00*

CO

2

for DCV

Control using a

Wall-Mounted

CO

2

Sensor

33ZCSENCO2

CO

2

for DCV

Control using a

Duct-Mounted

CO

2

Sensor

33ZCSENCO2†

and

33ZCASPCO2**

OR

CRCBDIOX005A00††

Fig. 32 — EconoMi$er IV Controller Potentiometer

and LED Locations

LED ON

LED ON

LED ON

LED ON

LED OFF

19

18

LED OFF

LED OFF

LED OFF

17

16

15

14

13

12

11

10

9

40

45

50

55

60

65

70

75

80

85

90

95

100

DEGREES FAHRENHEIT

mA

D

C

B

A

Fig. 33 — Outdoor Air Temperature

Changeover Set Points